Cinnamon and sweet potatoes are in this simple side dish soup. It's also good served with a sandwich for lunch or dinner.
In a saucepan, heat oil over medium heat. Add onion and cinnamon, and cook for 6 minutes. Stir in beans, chicken broth, and sweet potato. Bring mixture to a boil; reduce heat and simmer 10 minutes.
Let soup cool 5 minutes, puree in blender in two batches until smooth. Reheat on low until warm before serving. Top with yogurt, if desired.